JPH1066135A - Data communication control method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient data communication control method and device, in accordance with a state by deciding the order of data transmission in accordance with a state at the time of transmitting data. SOLUTION: In a data communication control device consisting of a command station, a control station and at least one mobile station, the command station is provided with a radio channel supervisory part 26 which supervises the channel establishment between the control station and the mobile station, a transmission order scheduling part 24 which changes the transmission order of data, so that data which 1 is transmitted to a mobile station where a channel has been established, in accordance with a supervisory result of the part 26 may preferentially be transmitted and a transmitting and receiving part 32 which transmits the data whose transmission order is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an MCA (Multi Ch
The present invention relates to a method and apparatus for controlling data communication, and more particularly to a method and apparatus for controlling data transmission when data is transmitted from a command station to a mobile station.

[0002]

2. Description of the Related Art In a conventional MCA data communication method, when data is transmitted from a command station to a mobile station, the command station transmits the data to the mobile station in the order of data transmitted from the host terminal. The command station and the host terminal are connected by wire, and data transmission and reception are performed by wire transmission. Data transmission and reception between the command station and the mobile station are performed by wireless transmission. Generally, data transmission / reception is better when data is exchanged by wire transmission than by wireless transmission. Therefore, in a system in which data is transmitted from the host terminal to the mobile station via the command station as described above, especially when the traffic of data transmission is high, the command station must be temporarily It is necessary to provide a buffer for storing data.

FIG. 5 is a diagram for explaining a communication procedure when a line is normally established between a command station and a mobile station in the conventional MCA data communication control method. In this figure, data is transmitted from the host terminal to the command station,
This data is transmitted from the command station to mobile station A, mobile station B, mobile station C.
Will be described. First, the first data addressed to mobile station A, the first data addressed to mobile station B, the second data addressed to mobile station A, and the third data addressed to mobile station A from the host terminal to the command station. When the data and the first data addressed to the mobile station C are transmitted in order, the command station stores these data in a buffer and simultaneously transmits the first transmitted data, that is, the first data addressed to the mobile station A. In order to transmit data, a signal indicating a line establishment request is transmitted to mobile station A,
When a line establishment response signal returned from mobile station A is received, it is determined that a wireless line connection with mobile station A has been established, and the above data is transmitted.

After transmitting the above data, the command station performs a line establishment process with the mobile station B to transmit the next data stored in the buffer, that is, the first data addressed to the mobile station B. Transmit the above data. Next, the command station performs a line establishment process with the mobile station A to transmit the data stored in the buffer, that is, the second data addressed to the mobile station A.
Transmit the above data. In this way, the command station performs a line establishment process with each mobile station in the order of the data stored in the buffer and transmits the data in order.

FIG. 6 is a diagram for explaining a communication procedure when a line establishment process between a command station and a mobile station fails in the conventional MCA data communication control method. In this figure, data is transmitted from the host terminal to the command station as in the case described above, and this data is transmitted from the command station to the mobile stations A,
The case where the data is transmitted to mobile station B and mobile station C will be described. From the host terminal to the command station, the first data addressed to the mobile station A, the first data addressed to the mobile station B, the second data addressed to the mobile station A, and the The third data and the first data addressed to the mobile station C are transmitted in order, and are stored in the buffer in the order in which each data was transmitted.

In order to transmit the first data stored in the buffer, that is, the first data addressed to mobile station A, the command station sends a line establishment request signal to establish a line with mobile station A. Send. When the mobile station A is outside the communication range and cannot receive the transmitted line establishment request signal, or when the mobile station A is in a building and cannot receive the line establishment request signal transmitted from the command station with a weak electric field. When a failure occurs, such as when the command station cannot receive the line establishment response signal transmitted from the mobile station A due to a weak electric field, the mobile station returns the line establishment response signal from the mobile station A even after a predetermined time has elapsed. Therefore, a line establishment request signal is transmitted again. The command station,
The above operation is performed a predetermined number of times.

If the line establishment response signal is not returned after transmitting the line establishment request signal a predetermined number of times as described above, the command station stops the line establishment process with the mobile station A, and the next data, ie, the mobile station B In order to transmit the destination data, a process for establishing a line with the mobile station B is performed. If the next data is the second data addressed to the mobile station A, a process for establishing a line with the mobile station A is performed again.

The conventional MCA communication is disclosed in, for example, Japanese Patent Application Laid-Open No. 05-014275 and
19337 and the like.

[0009]

In the conventional data communication control method and apparatus, data is transmitted to each mobile station basically in the order of data transmitted from the host terminal. When data destined for the mobile station is stored discontinuously, a line establishment process was performed each time to transmit each data,
There was a problem of inefficiency.

When data directed to the same mobile station is continuous in the buffer of the command station, when the line establishment with the mobile station fails, or when the probability of the line establishment is low,
Since the command station re-performed the line probability processing for the mobile station, there was a problem that the efficiency was poor. In the MCA data communication device, since a plurality of channels are shared by a plurality of users, and there is a limit to one communication time,
It is necessary to efficiently perform data communication for a given channel within a predetermined time.

The present invention has been made in view of the above circumstances, and determines an order of data transmission according to a situation at the time of data transmission, thereby achieving an efficient data communication control method and apparatus according to the situation. The purpose is to provide.

[0012]

According to one aspect of the present invention, there is provided a data communication apparatus for controlling communication of a data communication control device including a command station, a control station, and at least one mobile station. In the control method, a line establishment between the control station and the mobile station is monitored, a data order to be transmitted is changed according to a result of the monitoring, and data to be transmitted to the mobile station with the line established is transmitted preferentially. It is characterized by the following. According to a second aspect of the present invention, in the data communication control method according to the first aspect, the command station has a buffer for storing data to be transmitted, and the data transmitted by changing the storage order of the data stored in the buffer. The order is changed. According to a third aspect of the present invention, in the data communication control method according to the first or second aspect, when the line establishment fails, data to be transmitted to another mobile station is preferentially transmitted, and after a predetermined time has elapsed. The data to be transmitted to the mobile station for which the line establishment has failed is transmitted again. According to a fourth aspect of the present invention, in the data communication control device including a command station, a control station, and at least one mobile station, the command station monitors a radio channel for establishing a line between the control station and the mobile station. And a changing means for changing a transmission order of data so that data to be transmitted to a mobile station established with a line according to a monitoring result of the radio line monitoring unit is transmitted preferentially, and the transmission order is changed. Transmitting means for transmitting data. According to a fifth aspect of the present invention, in the data communication control device according to the fourth aspect, there is provided a buffer for storing data to be transmitted to the mobile station, and the changing means changes the storage order of the data stored in the buffer. It is characterized by the following.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a data communication control method and apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing the overall configuration of the data communication control device according to one embodiment of the present invention. The data communication control device shown in FIG. 2 includes a host terminal 2, a command station 4, a control station 6, a mobile station 8-1, a mobile station B8-2, and a mobile station C8-.
3, ... The control station 6 is a command station 4 or a mobile station 8
-1, automatically selecting a vacant channel in response to a communication request from mobile station B8-2, mobile station C8-3,.
Command station 4 or mobile station 8-1, mobile station B8-2, mobile station C
8-3,..., And returns information indicating that the line has been established or has not been established.

The command station 4 stores data transmitted from the host terminal 2, and a data adapter 4 a for controlling the transmission order of the stored data and a wireless device for wirelessly transmitting and receiving data to and from the control station 6. 4b. The mobile station 8-1, mobile station B8-2, mobile station C8-3,... Each include a terminal 8a, a data adapter 8b, and a radio 8c. When the data transmitted from the terminal 8b is transmitted from the wireless device 8c, the data adapter 8b controls so that communication can be performed normally, and also transmits the data transmitted from the control station 6 and received by the wireless device 8c to the terminal 8a. Output to

Next, the internal configuration of the command station 4 will be described in detail. FIG. 1 is a block diagram showing the internal configuration of the command station 4 and a diagram describing the order of transmission data at the time of transmission. FIG.
2, the interface 20, the buffer 22, the transmission order planning unit 24, and the wireless line monitoring unit 26 are provided in the data adapter 4a shown in FIG. 2, and the wireless line control unit 30, the transmitting / receiving unit 32, and the antenna 34 Machine 4b. The interface 20 relays data transmitted from the host terminal 2 and data transmitted to the host terminal. A buffer 22 stores data transmitted from the host terminal 2.

Further, the transmission order planning unit 24
The transmission order of the data to be transmitted to the control station 6 in FIG. 2 is determined based on a line establishment signal output from a radio line monitoring unit 26 described later with respect to the data stored in 2. The wireless line monitoring unit 26 monitors the wireless line control unit 30,
It detects which mobile station has established a line and outputs the line establishment signal to the transmission order planning unit 24.

When there is a transmission request, the radio channel control unit 30 automatically selects a vacant channel and selects a vacant channel between the mobile stations A8-1, B8-2, C8-3,. Establish a line. The transmitting / receiving unit 32 transmits data output from the wireless channel control unit 30 from the antenna 34, and transmits data received by the antenna 34 to the host terminal 2.

A data communication control method used in the data communication control device according to one embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 5 is a diagram for explaining a communication procedure when a line establishment process is normally performed between a command station and a mobile station in the data communication control method according to one embodiment of the present invention. In FIG. 3, the first data addressed to the mobile station A, the first data addressed to the mobile station B, the second data addressed to the mobile station A, the address addressed to the mobile station A via the interface 20 from the host terminal 2 The following describes a case where the third data and the first data addressed to the mobile station C are sequentially transmitted, and the respective data are stored in the buffer 22 in this order. The host terminal, command station, mobile station A, mobile station B, and mobile station C in FIGS. 3 and 4 are the host terminal 2, command station 4, and mobile station A8- in FIG.
1, mobile station B8-2 and mobile station C8-3.

First data stored in the buffer 22,
That is, the first data addressed to the mobile station A is stored in the transmission order planning unit 24.
And, it is transmitted to the transmission / reception unit 32 via the wireless channel control unit 30. At this time, all processes such as line establishment are performed by the wireless line control unit 30. The wireless line monitoring unit 26 monitors the wireless line control unit 30 and detects that a line has been established with the mobile station A. When the establishment of a line with mobile station A is detected, radio line monitoring section 26 outputs a line establishment signal indicating that the line has been established with mobile station A to transmission order planning section 24.

Upon receiving a line establishment signal indicating that a line has been established with the mobile station A from the radio line monitoring unit 26, the transmission order planning unit 24 searches for data stored in the buffer 22, and It is determined whether there is data addressed to the station A. When the data stored in the buffer 22 includes data destined for the mobile station A, the transmission order planning unit 24 transmits the first data destined for the mobile station A, and then transmits the second data destined for the mobile station A. Of the data is transmitted. When the transmission of the second data addressed to the mobile station A is also completed normally, the third data transmission to the mobile station A is performed.

As described above, when data addressed to a mobile station with an established line is stored in the buffer 22, data addressed to that mobile station is transmitted with priority. When there is no more data destined for the mobile station A among the data stored in the buffer 22, the transmission order planning unit 24 performs the transmission processing in the order normally transmitted from the host terminal.

Next, in the same way as shown in FIG.
Data of the first case, data of the first case addressed to mobile station B, mobile station A
In this case, the second data addressed to the mobile station A, the third data addressed to the mobile station A, and the first data addressed to the mobile station C are sequentially transmitted, and the respective data are stored in the buffer 22 in this order. Next, a communication procedure when the line establishment process between the command station and the mobile station fails will be described. FIG. 4 is a diagram for explaining a communication procedure when a line establishment process between a command station and a mobile station fails in the data communication control method of the present invention.

The data initially stored in the buffer 22,
That is, the first data addressed to the mobile station A is transmitted by the transmission order planning unit 24.
If the wireless channel control unit 30 fails to establish a line with the mobile station A, the wireless channel monitoring unit 26 establishes a line with the mobile station A. Detect failure. The wireless line monitoring unit 26 that has detected the failure in establishing the line with the mobile station A outputs a line establishment signal indicating that the line establishment with the mobile station A has failed to the transmission order planning unit 24.

When a line establishment signal indicating that line establishment with mobile station A has failed is output from radio line monitoring unit 26 to transmission order planning unit 24, transmission order planning unit 24 is stored in buffer 22. Then, it is determined whether the data to be transmitted next is data addressed to the mobile station A.
If the next data is data other than the mobile station A, for example, the data addressed to the mobile station B, the transmission processing is directly performed on the mobile station B. At this time, the transmission processing for the data addressed to the failed mobile station A is delayed by the number of data set in advance.

For example, if the setting is delayed by one data, after the data transmission to the mobile station B is completed, the data transmission processing to the mobile station A, which failed last time, is performed. Similarly, as described above, when the transmission order planning unit 24 receives the line establishment signal indicating that the line establishment has failed with the mobile station A, searches the buffer 22, and finds that the next data is the mobile station A. , The second data addressed to mobile station A is also
Along with the data of the item, a process of delaying by a predetermined amount of data and transmitting data addressed to another mobile station preferentially is performed. In this way, data destined for another mobile station is transmitted with priority over data destined for the mobile station for which the line establishment has failed.

[0026]

As described above, according to the present invention,
By successively transmitting data addressed to the same mobile station after the line is established, the line establishment process becomes unnecessary for the second and subsequent cases.
Therefore, when a plurality of data destined for the same mobile station are discontinuously stored in the buffer of the command station, efficiency is improved by continuously transmitting the discontinuously stored data. . This is because it is more efficient to continuously transmit to the same mobile station with a established line, considering that the line establishment with another mobile station fails.

A mobile station that has failed to establish a line once
Since the electric field and the possibility of being out of the service area are high, when the line establishment to the mobile station fails, when a plurality of data destined for the same mobile station are continuously stored in the buffer of the command station,
By prioritizing and transmitting data of another mobile station, the transmission efficiency is improved. This is because it is more efficient to give priority to the data if there is data addressed to another mobile station, rather than performing the line establishment process for the mobile station continuously.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic internal configuration of a command station 4 and a diagram describing the order of transmission data at the time of transmission.

FIG. 2 is a block diagram illustrating an overall configuration of a data communication control device according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining a communication procedure when a line establishment process is normally performed between a command station and a mobile station in the data communication control method according to the embodiment.

FIG. 4 is a diagram for explaining a communication procedure when a line establishment process between a command station and a mobile station fails in the data communication control method of the present invention.

FIG. 5 shows a conventional MCA data communication control method.
FIG. 7 is a diagram for explaining a communication procedure when a wireless line connection is normally established between a command station and a mobile station.

FIG. 6 shows a conventional MCA data communication control method.
FIG. 6 is a diagram for explaining a communication procedure when establishment of a wireless channel connection between a command station and a mobile station fails.

[Explanation of symbols]

 4 Command Station 6 Control Station 2-1 to 8-3 Mobile Station 22 Buffer 24 Transmission Order Planning Unit (Change Means) 26 Radio Line Monitoring Unit 32 Transmission / Reception Unit (Transmission Means)

Claims (5)

[Claims] 1. A data communication control method for controlling communication of a data communication control device comprising a command station, a control station, and at least one mobile station, comprising: monitoring a line establishment between the control station and the mobile station; A data communication control method characterized by changing the order of data to be transmitted according to the result of monitoring, and preferentially transmitting data to be transmitted to a mobile station with a channel established. 2. The command station according to claim 1, wherein the command station has a buffer for storing data to be transmitted, and changes a storage order of the data stored in the buffer to change a data order to be transmitted. Data communication control method. 3. When the line establishment fails, transmitting data to be transmitted to another mobile station preferentially, and after a lapse of a predetermined time, transmitting data to be transmitted to the mobile station whose line establishment has failed again. 3. The data communication control method according to claim 1 or 2, wherein 4. A data communication control device including a command station, a control station, and at least one mobile station, wherein the command station includes: a radio line monitoring unit that monitors the establishment of a line between the control station and the mobile station; Changing means for changing a transmission order of data so that data to be transmitted to a mobile station established in accordance with a monitoring result of the radio line monitoring unit is transmitted preferentially; and transmitting the data whose transmission order has been changed. A data communication control device comprising: 5. The apparatus according to claim 4, further comprising a buffer for storing data to be transmitted to said mobile station, wherein said changing means changes a storage order of data stored in said buffer. Data communication control device.